Gelatin subbing composition



Feb. 8, 1949.` R.' P. EASTON 2,461,467

I GELATIN SUBBING CUMPOSSITION Filed Nov. s. 1945 A LleHT smash-NE' EMULS\N LAY ER GELNrm- HETERocYmc I i NlTRoGLNous ems:

Illllllllllll-llllllllllllllllllllllllllllllll' "f\ SUPPORT y Fiep-2 mem' SENSH'NE 3 EMULS\0N LAYER Nrmoaenous BASE.

Suma LAYER l/ 'f A IsuPPom l GELATm-KHETERocNcmc NH'RQGENOUS BASE. SUBBlNe LAYER JNVENToR RUSSELL E EAS-rm Patented Feb. 8, 1949 naar GELATIN SUBBING COMPOSITION Russell P. Easton, Binghamton, N. Y., assignor to General Aniline & Film Corporation, New York, N. Y., a, corporation of Delaware Application November 8, 1945, Serial No. 627,450

(Cl. 10G-135) 3 Claims. l

This invention relates to photographic film and particularly to subbing compositions therefor.

It is known that a gelatino silver-halide emulsion will not adhere to an untreated lm base. An intermediate or subcoating layer` is necessary to prevent frilling of the gelatin layer when wet. or stripping when dry. Since hardened gelatin, as used for glass plates does not adhere to a film base, it is necessary touse a mixture of gelatin with an organic solvent for the material of the film base, such as acetone, ethyl acetate, an alcohol-ether or an alcohol-acetone mixture. Gelatin is insoluble in these organic solvents and the film base is insoluble in water, but it is possible to prepare dispersons consisting of gelatin in a mixture of one of the organic solvents and water with a volatile organic acid, such as acetic acid, and the like, as a dispersing agent.

Many volatile and non-volatile organic acids have heretofore been used as dispersing agents s for the gelatin in subbing compositions.' It has been found, however, that the use of these acids causes a decrease in sensitivity and artificial ageing of the gelatine silver-halide emulsion layer. This-effect is due primarily to the acidic nature of the dispersingV agent. Moreover, subbing solutions containing a dispersing agentpossessing acidic characteristics have the tendency to corrode the film-making machinery and the solvent recovery system which is customarily a part thereof.

The present invention has as anobject to over come the above-mentioned diiculties and to provide a method of dispersing gelatin in a subbing composition by means of dispersing agents, which will not desensitize and artificially age the gelatino silver-halide emulsion layer and which will not corrode the nlm-making machinery or solvent recovery system connected therewith.

Another object is to provide a non-desensitizing, non-corrosive dispersing agent for gelatin in subbing compositions.

I A further object is to provide a new type of gel solution in which the gelatin is dispersed by means of a non-desensitizing, non-corrosive dis-t persing agent, which has no adverse effect upon photographic gelatino silver-halide emulsions.

Other objects will appear from the following description.

These objects are accomplished bythe use of heterocyclic nitrogenous bases as dispersing agents in gelatin subbing compositions. As suitable hydrogenated heterocyclic nitrogenous bases may be mentioned, N-methyl morpholine, pyr-.

. 2 roline, pyrrolidine, piperidine, N-methylpiperidine, 2methylpiperidine, and the like.

The amount of theabove-mentloned heterocyclic nitrogenous bases. which may be employed as a dispersing agent, may vary over a smallV range, such as for example, from about .0.04% to 1%, and preferably from 0.05% to 0.07%. Thegelatin may range -from about 0.5% to 1.5% and preferably from 0.5% to 10%, and thewater. from about 2.5% to 7.5%, the balance vbeing substantially an organic solvent or mixture of such solvents. All proportions are by Weight.

The subhing compositions are made by mixing the components in variouswaysQin proportions so as to form a free flowing composition whichw dries or sets within a reasonable length of time and forms a thin layer 'on a film base. vIngeneral, it is desirable to dissolve the heterocyclic nitrogenous base( dispersing agent) in water and add to it the gelatin until the gelatin is dispersed. Slight warming and agitation will facilitate the dispersion of thegelatin in the aque y ous solution of the heterocyclic nitrogenousbase. Theorganic solvent or mixtures thereof are then mixed with the `aqueous dispersion of gelatin, and the solution thusl obtained is deposited .on a film Ibase in any convenient manner, such as" by beading, immersion, roll application, or other# wise, the subbing operation preferably being car' f ried out in connection' with, or as a part of,` the process .of making the film support'itself. The i' subbing solutions made up as above described-4 are milky-white dispersions of gelatin in the sol'- vent mixture and have 'a pH of about '7.0 or,v slightly above depending, of course. upon 'the concentration of the heterocyclic nitrogenous base employed.

The lm'bas'es used in accordance Withthisv invention are the cellulose derivatives, e. g., cel'V4 vlulose nitrate, cellulose acetate, and other lower 4fatty acid esters-of cellulose including simpleandl mixed esters, such as cellulose propionate, celA lulose butyrate, '/cellulose acetate-propionatey cellulose-acetate-butyrate andthe like, ether's of cellulose, such the methyl ether, ethyl ether and the like, and the-fusible, water-insoluble, synthetic linear. superpolymers used for iilm ele-I ments :as-described in United States Patents 2,0'll,250-,2,3` and 2,130,948. It Will be apprecie` ated that each different typeV of cellulose ester,:.

ether and mixtures thereof, including the syn-7" 4.such that it will have a solvent or ,at leesta-- softening or swelling action on the cellulose derivative and the synthetic linear superpolymer support so as to stick or anchor the gelatin upon the area of the support which has been softened or swollen.

Various solvents may be used for the gelatin subbing compositions and these solvents may be chosen according to; their actiomorrtheelnr support used For example; with aM cellulose acetate or a superpolymer base a low molecular weight alcohol, e. g., methanol, ethanol, and the likei,A or a ketone, such as acetone, on asmixture; et. alcohol and acetone may be employed. The ratio of alcohol to acetone rangessironraliout 50i-501%A to 'i5-25%, respectively. Withcellulose'y acetate?- propionate lm base, an alkyl ester, suchas, forv example, methyl acetate, ethyl: acetate butyli` acetate, and the like, either alone or with 1.4-dioxane, may be eiectively employed. It'may be mentioned at this point that the nature of the organic' solventor solvent mixture is; immaterial so long as it wetsT or bites into4 the cellulose derivative and' superpolymerfilm base material, and* tl'xef terni solventas' usedT in the claims: shoullibe soconstrued Sinceth'e materials:suit'.v alile: fori-lim liase-v andf their solvent properties are known, no dim'culty'i's presented" in# selecting a suitable. solvent orsolvent mixture for use in".

the. subbihg compositions;

In the" accompanying' drawingy the` various iig-- uresv are" section views of: anumber of modications. of pgliotograp'hic:` lm: madev accordingto'- the present invention.

As shownin Figure 1,.thesupport lk isprovidedL witlfa sublingjayer. or coating deposited from a dispersion ofgelatin anda heterocyelic nitrogenous based" with a lglit.-sensitive.l emulsion layer 3. deposited; on. said; subbing., layer..

Eigure 2. illustrates a lminwhicli the both sides ofithe. support. I. are coated with: subbing layers 2. and. L'. The. light-sensitiize. emulsionL layer; 3. is. deposited. on.1 the.` subbing. layer. 2..

When. a nlm. hase. is to. be.w prepared.. having., a gelatin; non-curl. backing layer, arr-- anti-static,

circhi ani antiz-halation.- layer. on the-sideopposite` the lightesensitive layer, the construction. illustraterinzEigunefz.iswpreferredr. Infths constructiene. the; suboingf rayer Z." serves as; ainon-curlf As an. alternatives. an; anti-static:

layer. or.` antiehala-tientlayer may-he deposited..

om the suiifbinglayen' 2f;

Tires iizcventiom hei turther iilustrated; but.k is not. intended, to; he limited. by the following examples..

Example I A- iilmfbase: of1 cellulose acetate was, coated witl thel following.4 sobbing solution-z.

Parts Gelatim 1.0;- Watgr 5ta? Pipeuidinfr. (L05 M'gthgmg-L 74245? Acetone 19:5@

A iilrny braiseA oicellul'ose acetateepropionate having' a-rr acety'll content of-`130%'- was-coatediwith tire foIlow-ii-lgfv sobbing* soiutorr:

1 thereof;

Parts Gelatin 1.0

Water 5 0 Pyrroline 0.07 Acetone '74.00 Ethanol 20.0

After. the; subbing layerT had.. dried.. the usual lightesensitive emulsion layerwas coated' directly on it. After exposure and processing the emulsion adhered tenaciously to the cellulose ace tate-propionate lm support.

Example III .PL lm. base prepared from a synthetic linear f superpolymer i; e., polyhexamethylene adipamlde,

of4 an intrinsic viscosity of 1.12, was coated with the following; subbing solution:

Parts Gelatin 10 Water 5 0 Pipeizidine 0.05- Mcthanol 32.00 Acetone 62.00-v

entirely satisfactory and toA givreK the customaryA physical requirements, such ash extremeV strength, exitiility, and good' Watereresistance.

The small quantity of1 heterocyclicnitrogenous' base may remain with the gelatin after evaporator of the` Water and'organicsolvent from` the subbing" compositiong has no adverse effect upon: the light-sensitive emulsion layer; nor'has the subbingf composition" any adverse eiect' upon the contaiire-rsin which itis stored:7 or upon the coating equipment employed. i

willi beiuiiderstood'Vv that wherein the claims appendedheretothe term1"'sulobing isf used, that sushi is: intended to include. theoperation of dispersiirg a sobbing layerffrom any one ofthe subbnigf: compositions prepared in accordanceI with. the; presentinvention.

While'- thepresentinvention: has been f described:

cnous: bases andi their use asdispersing. agents.

foitgelatin is notlimit'edfthereto andt'hat numerous; variations and# modifications described. in the foregoing specificationamay bemade; As forex-` ample, ai mixtureot twoor more-oi the heterocyclicnitrcgenous. gases may loeem'ployed as. diss persing.Z agents.

It also; understood. thatall the broad` examples oithe presentinyention include: the` pretur-v ration of' gelatin solutions in. generaL. in which. the.. gelatin. is.. dispersed.. in the, solvent by: means ofA heterocyclic nitrogenous. bases, or mixtures- All. such. modifications. and variationsarewithin-.thescope oi. the invention as defined. by theappendedj claims.

Iu claim.:

l. A gelatin composition, suitable for. subbing.

a photographic cellulose derivative lmzbase, consisting of' a small amount. of. water, a volatile.

organic solvent for said lrn base incapabler 0i dissolving gelatin, andVv as a dispersing agent. for the Agelatin a hydrogenated. heterocyclic. nitrog,- cnous' base selected from theA class consisting of 5 N-methylmorpholine, pyrroline, pyrroldine, p- REFERENCES CITED perdme N'methylpiperidne and Z'methylpiper' The following references are of record in the idine. f h' 2. The composition as dened in claim 1 e o t 1s patent' wherein the hydrogenated heterocyclic nitroge- 5 UNITED STATES PATENTS nous base is piperidine. Number Name Date 3. The COmPOSiiOn as dened in Caim 1 2,363,892 Mollier Nov 28, 1944 wherein the volatile organic solvent is a. mixture 2,341,877 Middleton et a] Feb. 15, 1944 of methyl alcohol and acetone. lo 2,324,105 Nadeau et a1 July 13, 1943 2,322,027 Jelley et al. June 15, 1943 RUSSELL P EASTON 2,240,471 swan Apr, 29, 1941 2,126,305 Babcock Aug. 9, 1938 

